Its not very safe but is doable if you are not storing large amounts on it, exchange wallets are not safe but for a small time period it can be okay and it would not be bad.
In the most cases you should just transfer it as fast as possible.
For sure many of us are a bit cautious already for the past incidents with some 'trusted' exchange sites that has been hacked.
We may not know if they are really hacked or some other inside job happened. But still, if you want to trust exchange sites.
Trust at your own risk as many are saying here and we all warned them that it is a very risky thing to do.